Work has begun to construct the groundwater cut-off - an underground waterproof wall - around the area on Hungary's Paks nuclear power plant site where two new units are to be built. The wall will control the flow of groundwater into and out of the Paks II construction pit, once excavated.

Construction of the groundwater cut-off at the Paks II site gets under way (Image: Paks II)

The work began on 3 July by the general contractor of the project, JSC ASE, Rosatom's engineering division. Rosatom noted that the construction of the groundwater cut-off is "carried out in strict compliance with the licences issued by the Hungarian Atomic Energy Authority".

The groundwater cut-off is an engineering structure - an impervious wall - one metre thick and up to 32 metres deep, having a circumference of 2.5 kilometres. Its task is not only to keep groundwater out of the pit but also to prevent the groundwater level at the construction site from dropping, "which is a critical condition for the safe operation of the four operating units of the Paks NPP," Rosatom said.

"In parallel with the construction of the groundwater cut-off, preparatory work is underway to construct auxiliary buildings and facilities, concrete plant, warehouses and office buildings," it noted. "Following the construction of the groundwater cut-off and soil stabilisation, excavation works and preparation for the construction of the foundation slab will begin".

Hungary's Foreign and Trade Minister Peter Szijjártó said the soil excavation under unit 6 will start in August, while the finalisation of the licences required for the complete soil excavation is proceeding as planned.

In May, the European Union approved an amendment of contracts on the project for the new Russian-built nuclear units in Hungary. Many European Union countries have ended, or are in the process of ending, their nuclear energy links with Russia as a result of the war with Ukraine. Hungary, however, is pushing ahead with its project to install new nuclear capacity with Russia's Rosatom and has said it opposes the inclusion of nuclear in EU sanctions lists.

Szijjártó said the Russian government will approve the amendment to the financial agreement in a few days, which will be followed by the signing of the amended engineering, procurement and construction contract.

The Paks II project was launched in early 2014 by an intergovernmental agreement between Hungary and Russia for two VVER-1200 reactors to be supplied by Rosatom, with the contract supported by a Russian state loan to finance the majority of the project. The application was submitted in July 2020 to construct Paks II alongside the existing Paks plant, 100 kilometres southwest of Budapest on the banks of the Danube river. Hungary's National Atomic Energy Office issued the construction licence in August 2022. In January this year, Hungary's Energy Minister Csaba Lantos said the Paks II plant was now expected to be completed in 2032.

The existing four units at Paks are VVER-440 reactors that started up between 1982 and 1987 and produce about half of the country's electricity. Their design lifetime was for 30 years but that was extended in 2005 by 20 years to 2032 and 2037. In December, the Hungarian Parliament approved a proposal to further extend their lifespan, which means preparations can begin on operating the plant into the 2050s.

Researched and written by World Nuclear News

Date: Friday, 07 July 2023
Original article: world-nuclear-news.org/Articles/Preparatory-works-begin-at-Paks-II-site